Reaction turbine

ABSTRACT

A reaction turbine, according to the present invention, includes first and second rotor plates, which are coupled together to form an integrated rotor, and an inner flow path including a combination of first and second flow paths, which are formed on the surfaces of the first and second rotor plates that face each other, respectively, thereby enabling easier manufacturing into a form desired by a designer by eliminating the limitation of a cross-sectional shape of the inner flow path. In addition, a cross section of each of the first and second flow paths can be formed into a semicircular shape thus yielding a circular shape for the inner flow path, which is formed by combining the first and second flow paths, thereby effectively enhancing the performance of a turbine by minimizing pressure loss of a working fluid that passes through the inner flow path.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage Patent Application of PCT International Patent Application No. PCT/KR2013/003264 filed on Apr. 18, 2013 under 35 U.S.C. §371, which claims priority to Korean Patent Application No. 10-2012-0049631 filed on May 10, 2012, which are all hereby incorporated by reference in their entirety.

BACKGROUND

The present invention relates to a reaction turbine, and more particularly, to a reaction turbine that generates a rotational force using a repulsive force when a working fluid, such as steam, gas, or compressed air, is injected.

In general, a steam turbine is one of motor techniques that convert thermal energy of steam into a mechanical work. The steam turbine jets and expands high-temperature and high-pressure steam generated in a boiler from nozzles or fixed wings, makes a high-speed steam flow collide with rotating turbine wings and rotates a turbine shaft by an impulse or rebound action. Thus, the steam turbine is configured of nozzles that convert the thermal energy of the steam into velocity energy and turbine wings that convert the velocity energy into a mechanical work. Examples of the steam turbine include an impulse turbine that drives the turbine wings using only an impulsive force and a rebound turbine or a reaction turbine that is driven by a rebound force.

Korean Patent Registration No. 10-1052253 discloses a reaction turbine, wherein two or more injection rotation portions within a housing communicate with each other and are disposed along a radial direction in a multi-stage manner and rotate by reaction of an injection action of a fluid injected through an injection flow path of each injection rotation portion. However, when the capacity of the turbine is changed, it is difficult to share each component, such as the injection rotation portion.

The present invention provides a reaction turbine in which components can be shared so that a turbine having various capacities can be manufactured and the performance of the turbine can be enhanced by minimizing pressure loss that may occur when a working fluid flows.

According to an aspect of the present invention, there is provided a reaction turbine including: a housing in which a housing inlet and a housing outlet are formed and a housing flow path that communicates the housing inlet and the housing outlet so that a high-pressure working fluid introduced into the housing inlet is capable of moving in a direction of the housing outlet; a rotation shaft that passes through the housing and is rotatably coupled to the housing; and a rotor that is integrally coupled to the rotation shaft within the housing flow path and rotates the rotation shaft as the working fluid introduced from a center side of the rotor in an axial direction is injected toward an outer circumference side of the rotor, wherein the rotor may include first and second rotor plates that are coupled to each other in the axial direction, and first and second flow paths may be formed on surfaces of the first and second rotor plates that face each other, respectively, and a combination of the first and second flow paths may constitute an inner flow path on which the working fluid is guided.

According to another aspect of the present invention, there is provided a reaction turbine including: a housing in which a housing inlet and a housing outlet are formed and a housing flow path that communicates the housing inlet and the housing outlet so that a high-pressure working fluid introduced into the housing inlet is capable of moving in a direction of the housing outlet; a rotation shaft that passes through the housing and is rotatably coupled to the housing; and a rotor that is integrally coupled to the rotation shaft within the housing flow path and rotates the rotation shaft as the working fluid introduced from a center side of the rotor in an axial direction is injected toward an outer circumference side of the rotor, wherein the rotor may include first and second rotor plates that are coupled to each other in the axial direction, and an inner flow path on which the working fluid is guided, may be formed on a surface of the second rotor plate toward the first rotor plate, and the first rotor plate may be formed to cover an entire surface of the inner flow path.

According to still another aspect of the present invention, there is provided a reaction turbine including: a housing in which a housing inlet and a housing outlet are formed and a housing flow path that communicates the housing inlet and the housing outlet so that a high-pressure working fluid introduced into the housing inlet is capable of moving in a direction of the housing outlet; a rotation shaft that passes through the housing and is rotatably coupled to the housing; and a rotor assembly that includes a plurality of rotors, which are stacked and disposed in a multi-stage manner along an axial direction within the housing flow path that are integrally coupled to the rotation shaft, and that rotate the rotation shaft as the working fluid introduced from a center of each of the plurality of rotors in the axial direction is injected toward an outer circumference side of each rotor, wherein the plurality of rotors may be integrally formed when two rotor plates are coupled to each other in the axial direction, and first and second flow paths of which cross sections are symmetrical with respect to each other, may be formed on surfaces of the rotor plates that face each other, and a combination of the first and second flow paths may constitute one inner flow path.

In a reaction turbine according to the present invention, first and second rotor plates are coupled together to form an integrated rotor, and an inner flow path including a combination of first and second flow paths, which are formed on the surfaces of the first and second rotor plates that face each other, respectively, thereby enabling easier manufacturing into a form desired by a designer by eliminating the limitation of a cross-sectional shape of the inner flow path. In addition, a cross section of each of the first and second flow paths can be formed into a semicircular shape thus yielding a circular shape for the inner flow path, which is formed by combining the first and second flow paths, thereby effectively enhancing the performance of a turbine by minimizing pressure loss of a working fluid that passes through the inner flow path.

In addition, in the reaction turbine according to the present invention, when a rotor includes first and second rotor plates and an inner flow path is formed only on one rotor plate, a forming work and time of the inner flow path can be reduced. Also, the cross section of the inner flow path is formed into a semicircular shape so that pressure loss of the working fluid can be reduced.

Also, the cross section of each of the first and second flow paths formed on the first and second rotor plates is formed into a semicircular shape, and the first and second flow paths each have an involute curve shape so that a change in flow paths of the working fluid is more gentle and pressure loss that occurs due to the change in flow paths can be minimized and thus the performance of the turbine can be enhanced.

Furthermore, since a plurality of rotors are stacked in a multi-stage manner along an axial direction, the number of rotors can be increased or decreased according to the capacity of the turbine so that the turbine having various capacities can be manufactured, components can be shared and thus manufacturing costs can be reduced.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a reaction turbine according to a first embodiment of the present invention;

FIG. 2 is an enlarged view of a portion A of FIG. 1;

FIG. 3 is a plan view of a first rotor plate illustrated in FIG. 1;

FIG. 4 is a cross-sectional view taken along a line B-B of FIG. 2;

FIG. 5 is a cross-sectional view of a part of first and second rotor plates according to a second embodiment of the present invention;

FIG. 6 is a cross-sectional view taken along a line C-C of FIG. 5;

FIG. 7 is a cross-sectional view of a part of first and second rotor plates according to a third embodiment of the present invention;

FIG. 8 is a cross-sectional view taken along a line D-D of FIG. 7;

FIG. 9 is a plan view of a first rotor plate according to a fourth embodiment of the present invention; and

FIG. 10 is a cross-sectional view taken along a line E-E of FIG. 9.

DETAILED DESCRIPTION

Hereinafter, a reaction turbine according to the present invention will be described in detail with reference to embodiments illustrated in the accompanying drawings.

FIG. 1 is a cross-sectional view of a reaction turbine 1 according to a first embodiment of the present invention.

The reaction turbine 1 according to the present invention generates a rotational force using a working fluid including high-pressure steam or gas, or compressed air. The working fluid includes high-pressure steam or gas, or compressed air. Hereinafter, in the present embodiment, a case where the working fluid is steam, will be described.

In the reaction turbine 1, a rotation shaft 20 is rotatably coupled to a housing 10, and at least one or more rotors 200 are stacked on the rotation shaft 20 along an axial direction.

The housing 10 includes an inlet housing 15 in which a housing inlet 10 a is formed so that high-pressure steam that is the working fluid may be introduced into the inlet housing 15, an outlet housing 16 that is disposed at the other side of the inlet housing 15 and is spaced apart from the inlet housing 15 by a predetermined distance and has a housing outlet 10 b through which expanded low-pressure steam is discharged in the air or is recirculated, and intermediate housings 11, 12, 13, and 14 that are disposed between the inlet housing 15 and the outlet housing 16 and form a housing flow path 10 c on which the rotors 200 can rotate. At least one or more housing inlets 10 a may be provided, and in the present embodiment, one housing inlet 10 a is formed. At least one or more housing outlets 10 b may be provided, and in the present embodiment, one housing outlet 10 b is formed. The number of intermediate housings 11, 12, 13, and 14 that corresponds to the number of rotors 200 may be provided. In the present embodiment, four rotors 200 that will be described later are provided. Thus, four intermediate housings 11, 12, 13, and 14 are provided along the axial direction.

Separation plates 30 are respectively provided at both sides of four intermediate housings 11, 12, 13, and 14 so as to form the housing flow path 10 c together with the intermediate housings 11, 12, 13, and 14. The separation plates 30 each have a disc shape, and through holes are formed in the middle of the separation plates 30 so that a first rotor plate 211 that will be described later can be rotatably inserted into the separation plates 30 through the through holes. A sealing member 40 for preventing leakage of steam is inserted between the separation plate 30 and the first rotor plate 211. The sealing member 40 will be described in detail later. The sealing member 40 has a ring shape and is coupled to the separation plate 30 in the axial direction. The sealing member 40 is inserted into an inner circumferential surface of the separation plate 30 in the axial direction and then is fixedly installed using a fastening member, such as a bolt. The sealing member 40 is a Labyrinth seal having a shape in which a contact surface between the sealing member 40 and the first rotor plate 211 is minimized so that rotation of the first rotor plate 211 that will be described later can be easily performed.

A bearing module through which the rotation shaft 20 that have passed through the housing 10 passes, is installed in the inlet housing 15 and the outlet housing 16, respectively, and a bearing 21 that supports the rotation shaft 20 is disposed in the bearing module. Also, a mechanical seal 22 is disposed so as to prevent the working fluid in the inlet housing 15 and the outlet housing 16 from leaking toward the bearing module. Also, a sealing member 24 having a Labyrinth seal structure in which the sealing member 24 is installed between the mechanical seal 22 and the bearing 21 and prevents the working fluid that leaks from the mechanical seal 22 from being introducing into the bearing 21, is disposed in the bearing module.

The rotor 200 is integrally coupled to the rotation shaft 20 and rotates the rotation shaft 20 as the steam introduced from a center side of the rotor 200 in the axial direction is injected toward an outer circumference side of the rotor 200. The capacity of the turbine may be changed according to the number of rotors 200 coupled to the rotation shaft 20. That is, when the capacity of the turbine is small, the number of rotors 200 may be decreased, and when the capacity of the turbine is large, the number of rotors 200 may be increased.

A plurality of rotors 200 are stacked and disposed in a multi-stage manner along the axial direction within the housing flow path 10 c, and the steam injected from a rotor in the previous stage toward the outer circumference of each of the rotors 200 is introduced into a center of a rear rotor through the housing flow path 10 c. In the present embodiment, the rotor 200 includes four, i.e., first-stage, second-stage, third-stage, and four-stage rotors 210, 220, 230, and 240. The four, i.e., first-stage, second-stage, third-stage, and four-stage rotors 210, 220, 230, and 240 are disposed along the axial direction.

First and second rotors 211 and 212 of each of the first-stage, second-stage, third-stage, and four-stage rotors 210, 220, 230, and 240 are coupled together in the axial direction to form an integrated rotor. Hereinafter, configurations of the four, i.e., first-stage, second-stage, third-stage, and four-stage rotors 210, 220, 230, and 240 in which they each include first and second rotor plates 211 and 212, are similar. Thus, the first rotor plate 211 and the second rotor plate 212 of the first-stage rotor 210 will be described.

FIG. 2 is an enlarged view of a portion A of FIG. 1. FIG. 3 is a plan view of a first rotor plate illustrated in FIG. 1. FIG. 4 is a cross-sectional view taken along a line B-B of FIG. 2.

Referring to FIGS. 2 through 4, the first rotor plate 211 has a disc shape, and a first boss portion 211 b is formed in the center of the first rotor plate 211 and protrudes toward the housing inlet 10 a and constitutes a rotor introduction portion 201 into which the steam that is the working fluid is introduced, together with a second boss portion 212 b that will be described later. A first flow path 211 a is formed at a rear surface of the first rotor plate 211, i.e., at a surface that faces the second rotor plate 212. Since the shape of the first flow path 211 a corresponds to the shape of a second flow path 212 a that will be described later, the second flow path 212 a will be described with reference to FIG. 3.

A first nozzle portion 211 c having a smaller cross-sectional area than that of a discharge side of the first flow path 211 a is formed at the discharge side of the first flow path 211 a. That is, referring to FIG. 2, the first nozzle portion 211 c is formed as a groove having a smaller radius than that of the first flow path 211 a and thus increases flow velocity of the discharged fluid. The first nozzle portion 211 c is limited to having the shape of the groove formed in the first rotor plate 211. However, embodiments of the present invention are not limited thereto, and additional nozzles each having a small radius part may be installed in the first nozzle portion 211 c.

The first rotor plate 211 may be manufactured using a casting method, and the first flow path 211 a may be formed when a casting work is performed and may be finished using a ball end mill. Of course, embodiments of the present invention are not limited thereto, and the first flow path 211 a may be manufactured in any one of methods, whereby a groove may be formed in a surface from the first rotor plate 211 to the second rotor plate 212. Also, in the present embodiment, the first rotor plate 211 is finished using the ball end mill. However, embodiments of the present invention are not limited thereto, and the first rotor plate 211 may not be finished or may be finished using a different method. When the first nozzle portion 211 c is finished, a ball end mill having a smaller diameter than that of the ball end mill used to form the first flow path 211 a is used.

The second rotor plate 212 has a disc shape, and the second boss portion 212 b is formed on an inner circumferential surface of the second rotor plate 212 so that the rotation shaft 20 can be coupled to the second rotor plate 212. A shaft insertion hole 212 d into which the rotation shaft 20 is inserted, is formed in the second boss portion 212 b, and a key hole 212 e into which a key of the rotation shaft 20 is inserted, is formed in an inner circumferential surface of the shaft insertion hole 212 d. An outer circumferential surface of the second boss portion 212 b and an inner circumferential surface of the first boss portion 211 b constitute the rotor introduction portion 201. A second flow path 212 a is formed on the entire surface from the second rotor plate 212 to the first rotor plate 211. Referring to FIG. 3, the second flow path 212 a is formed to guide the working fluid introduced from the rotor introduction portion 201 outwards. That is, the second flow path 212 a extends from an outer circumferential surface of the rotor introduction portion 201 and is formed to be close to a circumferential direction from the outer circumferential surface of the second rotor plate 212.

A second nozzle portion 212 c having a smaller cross-sectional area than that of a discharge side of the second flow path 212 a is formed at the discharge side of the second flow path 212 a. That is, the second nozzle portion 212 c is formed as a groove having a smaller radius than that of the second flow path 212 a and increases flow velocity of the discharged fluid. The second nozzle portion 212 c is limited to having the shape of the groove formed in the second rotor plate 212. However, embodiments of the present invention are not limited thereto, and of course, additional nozzles each having a small radius part may be installed in the second nozzle portion 212 c.

The second rotor plate 212 may be manufactured using a casting method, like in the first rotor plate 211. The second flow path 212 a may be formed when a casting work is performed and may be finished using a ball end mill. Of course, embodiments of the present invention are not limited thereto, and the second flow path 212 a may be manufactured in any one of methods, whereby a groove may be formed in a surface from the second rotor plate 212 to the first rotor plate 211. Also, in the present embodiment, the second rotor plate 212 is finished using the ball end mill. However, embodiments of the present invention are not limited thereto, and the second rotor plate 212 may not be finished or may be finished using a different method. When the second nozzle portion 212 c is finished, a ball end mill having a smaller diameter than that of the ball end mill used to form the second flow path 212 a is used.

When the first rotor plate 211 and the second rotor plate 212 are coupled to each other in the axial direction, the first flow path 211 a and the second flow path 212 a are symmetrical with respect to each other based on a surface on which the first and second rotor plates 211 and 212 are coupled together, and constitute one inner flow path 202. That is, the first flow path 211 a and the second flow path 212 a have cross sections that are symmetrical with respect to each other based on the surface on which the first and second rotor plates 211 and 212 are coupled together. In the present embodiment, a cross section of each of the first flow path 211 a and the second flow path 212 a is formed into a semicircular shape. As the cross section of each of the first flow path 211 a and the second flow path 212 a is formed into the semicircular shape, when the first and second flow paths 211 a and 212 b are combined with each other, the inner flow path 202 has a circular cross section. However, embodiments of the present invention are not limited thereto, and the cross-sectional shape of the inner flow path 202 is a circular shape, wherein the cross sections of the first and second flow paths 211 a and 212 a may not be symmetrical with respect to each other. Also, the cross sections of the first and second flow paths 211 a and 212 a are symmetrical with respect to each other and constitute an arc shape (not the semicircular shape) or have rounded edges so that pressure loss of the working fluid can be reduced.

The rotor 210 having the above configuration includes first and second rotor plates 211 and 212, and the first and second flow paths 211 a and 212 a formed in the first and second rotor plates 211 and 212 are combined with each other and constitute one inner flow path 202. Thus, the cross-sectional shape of the inner flow path 202 may be a circular shape so that the pressure loss of the working fluid is minimized and performance of the turbine can be enhanced.

An operation of the reaction turbine having the above configuration according to an embodiment of the present invention will be described as below.

When high-pressure steam generated in a boiler is supplied to the housing inlet 10 a of the housing 10 through a pipe, the steam is introduced into the rotor introduction portion 201 of the first-stage rotor 210 in the axial direction. The steam introduced into the rotor introduction portion 201 in the axial direction is distributed into a plurality of inner flow paths 202. The distributed steam passes through the plurality of inner flow paths 202, is moved toward an outer circumference side of the first-stage rotor 210, and is injected toward the housing flow path 10 c at high velocity along a circumferential direction of the rotor 200.

The steam injected toward the outer circumference side of the first-stage rotor 210 is introduced into the center of the second-stage rotor 220 disposed in the rear of the first-stage rotor 210, and the steam introduced into the second-stage rotor 220 passes through the inner flow paths 202 and is injected toward the outer circumference side of the second-stage rotor 220. The steam injected toward the outer circumference side of the second-stage rotor 220 is introduced into the center of the third-stage rotor 230, passes through the inner flow paths 202 and then is injected toward an outer circumference side of the third-stage rotor 230. The steam injected toward the outer circumference side of the third-stage rotor 230 is introduced into the center of the fourth-stage rotor 240, passes through the inner flow paths 202 and then is injected toward an outer circumference side of the fourth-stage rotor 240. The steam injected toward the outer circumference side of the fourth-stage rotor 240 is discharged to an outer portion of the housing 10 through the housing outlet 10 b. The steam discharged to the outer portion of the housing 10 is discharged in the air or is recovered by a steam condenser (not shown) and then is circulated in the boiler. This operation is repeatedly performed.

The first-stage, second-stage, third-stage, and fourth-stage rotors 210, 220, 230, and 240 rotate by a reaction generated when the high-pressure steam is injected in the circumferential direction. A rotational force generated in this case is transferred to the rotation shaft 20 to which the first-stage, second-stage, third-stage, and fourth-stage rotors 210, 220, 230, and 240 are coupled. When the rotation shaft 20 rotates together with the first-stage, second-stage, third-stage, and fourth-stage rotors 210, 220, 230, and 240, the rotational force is transferred to the outside.

In the reaction turbine having the above-described configuration, cross sections of the inner flow paths 202 through which the steam passes, have circular shapes. Thus, the pressure loss of the working fluid that passes through the inner flow paths 202 is reduced so that performance of the turbine can be enhanced.

FIG. 5 is a cross-sectional view of a part of first and second rotor plates according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view taken along a line C-C of FIG. 5.

A rotor 310 according to the second embodiment of the present invention includes first and second rotor plates 311 and 312. The rotor 310 according to the second embodiment of the present invention is different from the rotor 200 according to the first embodiment in that inner flow paths 302 are formed only on a surface of a second rotor plate 312 toward a first rotor plate 311, and the difference will be described in detail.

The first rotor plate 311 has a disc shape, and a first boss portion 311 a is formed in the center of the first rotor plate 311, protrudes toward the housing inlet 10 a and constitutes a rotor introduction portion 201 into which steam that is the working fluid is introduced, together with a second boss portion 312 a that will be described later.

The second rotor plate 312 has a disc shape, and the second boss portion 312 a is formed on an inner circumferential surface of the second rotor plate 312 so that a rotation shaft 20 can be coupled to the second rotor plate 312. An outer circumferential surface of the second boss portion 312 a and an inner circumferential surface of the first boss portion 311 a constitute a rotor introduction portion 201. The inner flow paths 302 are formed on a front surface of the second rotor plate 312 toward the first rotor plate 311. The inner flow paths 302 may have various cross-sectional shapes. Thus, in the present embodiment, the inner flow paths 302 have rectangular cross-sectional shapes. The inner flow paths 302 are formed in such a way that the surface toward the first rotor plate 311 is formed to be opened, and the inner flow paths 302 are covered by the first rotor plate 311. The second rotor plate 312 is manufactured using a casting method, and the inner flow paths 302 are formed when a casting work is performed. Of course, embodiments of the present invention are not limited thereto, and the inner flow paths 302 may be manufactured in any one of methods, whereby a groove may be formed in a surface from the second rotor plate 312 to the first rotor plate 311. Also, in the present embodiment, the inner flow paths 302 are not separately finished. However, embodiments of the present invention are not limited thereto, and the inner flow paths 302 may be finished so that their edges may be rounded so that the pressure loss of the working fluid can be reduced.

A nozzle portion 303 having a smaller cross-sectional area than that of the inner flow path 302 is formed at a discharge side of the inner flow path 302.

The rotor 410 having the above configuration includes the second rotor plate 312 in which the inner flow paths 302 are formed, and the first rotor plate 311 that covers the inner flow paths 302. As the rotor 310 includes first and second rotor plates 311 and 312, the inner flow paths 302 may be formed in various shapes. The inner flow paths 302 are formed only on the second rotor plate 312 so that a structure of the rotor 310 is simplified and a forming work and time can be reduced.

FIG. 7 is a cross-sectional view of a part of first and second rotor plates according to a third embodiment of the present invention. FIG. 8 is a cross-sectional view taken along a line D-D of FIG. 7.

A rotor 410 according to the third embodiment of the present invention includes first and second rotor plates 411 and 412. The rotor 410 according to the third embodiment of the present invention is different from that rotor 310 according to the second embodiment of the present invention in that inner flow paths 402 are formed only on a surface of the second rotor plate 412 toward the first rotor plate 411, wherein cross-sectional shapes of the inner flow paths 402 are semicircular shapes. The difference will be described in detail.

The first rotor plate 411 has a disc shape, and a first boss portion 411 a is formed in the middle of the first rotor plate 411 and protrudes toward a housing inlet 10 a. The first boss portion 411 a constitutes a rotor introduction portion 201 into which steam that is a working fluid is introduced, together with a second boss portion 312 a that will be described later.

The second rotor plate 412 has a disc shape, and a second boss portion 412 a is formed on an inner circumferential surface of the second rotor plate 412 so that a rotation shaft 20 can be coupled to the second rotor plate 412. An outer circumferential surface of the second boss portion 412 a and an inner circumferential surface of the first boss portion 411 a constitute the rotor introduction portion 201. The inner flow paths 402 are formed on a front surface of the second rotor plate 412 toward the first rotor plate 411. Cross sections of the inner flow paths 402 may have various shapes. Thus, in the present embodiment, the inner flow paths 402 have semicircular cross sections. The second rotor plate 412 may be manufactured using a casting method, and the inner flow paths 402 may be formed when a casting work is performed and may be finished using a ball end mill. Of course, embodiments of the present invention are not limited thereto, and the inner flow paths 402 may be manufactured in any one of methods, whereby a groove is formed in a surface from the second rotor plate 412 to the first rotor plate. Also, in the present embodiment, the inner flow paths 402 may be finished using the ball end mill. However, embodiments of the present invention are not limited thereto, and the inner flow paths 402 may not be finished and may also be finished using a different method.

A nozzle portion 403 having a smaller cross-sectional area than that of the inner flow path 402 is formed at a discharge side of the inner flow path 402. The cross-sectional shape of the nozzle portion 403 may be a semicircular shape, and the nozzle portion 403 may be finished using a ball end mill having a smaller diameter than that of the ball end mill used to finish the inner flow path 402.

The rotor 410 having the above configuration includes the second rotor plate 412 in which the inner flow paths 402 are formed, and the first rotor plate 411 that covers the inner flow paths 402. As the rotor 410 includes the first and second rotor plates 411 and 412, the inner flow paths 402 may be formed in various shapes, and the inner flow paths 402 are formed only on the second rotor plate 412 so that a structure of the rotor 410 is simplified and a forming work and time can be reduced. Also, as the cross section of the inner flow path 402 is formed into a semicircular shape, pressure loss of a working fluid can be reduced.

FIG. 9 is a plan view of a first rotor plate according to a fourth embodiment of the present invention. FIG. 10 is a cross-sectional view taken along a line E-E of FIG. 9.

A rotor according to the fourth embodiment of the present invention includes first and second rotor plates 511 and 512. First and second flow paths 510 and 502 are formed on surfaces of the first and second rotor plates 511 and 512 that face each other, and the first and second flow paths 510 and 502 are combined with each other and constitute one inner flow path 520 that guides the working fluid. The rotor according to the fourth embodiment of the present invention is different from the above embodiments in that at least a part of the first and second flow paths 510 and 502 has an involute curve shape. The difference will be described in detail. Hereinafter, shapes of the first and second flow paths 510 and 502 formed on the surfaces of the first and second rotor plates 511 and 512 that face each other, are similar, and thus, the second rotor plate 512 will be described.

As the second flow path 502 formed at the second rotor plate 512 has an involute curve shape, a change in directions of flow paths is gentle so that a pressure drop of steam caused by the change in the directions of flow paths can be reduced. An outer circumferential surface of the second flow path 502 is connected to an outer circumferential surface 501 a of a circle that constitutes the rotor introduction portion 501 so as to constitute at least one arc shape. A radius r₂ of an arc 505 is greater than an inner diameter r₁ of the rotor introduction portion 501. Also, a radius of a basic circle of an involute curve that constitutes the second flow path 502 is set to be smaller than the inner diameter r₁ of the rotor introduction portion 501.

A nozzle portion 503 having a smaller cross-sectional area than that of a discharge portion 502 b of the second flow path 502 is installed at the discharge portion 502 b of the second flow path 502. The nozzle portion 503 is disposed in an extension line of the second flow path 502, and the second flow path 502 and the nozzle portion 503 are placed in the same involute curve. Velocity energy and pressure energy of steam discharged by the nozzle portion 503 increase so that the steam can be injected at high velocity. However, embodiments of the present invention are not limited thereto, and additional nozzles each having a small radius may also be installed at the discharge portion 502 b of the second flow path 502 using a fastening member.

The second flow path 502 and the first flow path 510 have cross sections that are symmetrical with respect to each other based on a surface on which the first and second rotor plates 511 and 512 are coupled together.

In the present embodiment, referring to FIG. 10, cross-sectional shapes of the first flow path 510 and the second flow path 502 are semicircular shapes. As the cross-sectional shapes of the first flow path 510 and the second flow path 502 are semicircular shapes, when the first and second flow paths 510 and 502 are combined with each other, the inner flow path 520 has a circular cross section. However, embodiments of the present invention are not limited thereto, and the cross-sectional shape of the inner flow path 520 is a circular shape, wherein the cross sections of the first and second flow paths 510 and 502 are symmetrical with respect to each other. Also, the cross sections of the first and second flow paths 510 and 502 are symmetrical with respect to each other and constitute an arc shape (not the semicircular shape), or edges of the first and second flow paths 510 and 502 may be formed to be rounded so that the pressure loss of the working fluid can be reduced.

In the reaction turbine having the above configuration, each of the first and second flow paths 510 and 502 through which steam passes, has an involute curve shape. Thus, a change in flow paths of the steam that is guided from the center to an outer circumferential side of the turbine and is injected in a circumferential direction, is gentle so that the pressure loss can be reduced and performance of the turbine can be enhanced.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.

By using the present invention, a reaction turbine in which components can be shared so that a turbine having various capacities can be manufactured and pressure loss that occurs when a working fluid flows, is minimized so that performance of the turbine can be enhanced, can be manufactured. 

1. A reaction turbine comprising: a housing in which a housing inlet and a housing outlet are formed and a housing flow path that communicates the housing inlet and the housing outlet so that a high-pressure working fluid introduced into the housing inlet is capable of moving in a direction of the housing outlet; a rotation shaft that passes through the housing and is rotatably coupled to the housing; and a rotor that is integrally coupled to the rotation shaft within the housing flow path and rotates the rotation shaft as the working fluid introduced from a center side of the rotor in an axial direction is injected toward an outer circumference side of the rotor, wherein the rotor comprises first and second rotor plates that are coupled to each other in the axial direction, and first and second flow paths are formed on surfaces of the first and second rotor plates that face each other, respectively, and a combination of the first and second flow paths constitutes an inner flow path on which the working fluid is guided.
 2. A reaction turbine comprising: a housing in which a housing inlet and a housing outlet are formed and a housing flow path that communicates the housing inlet and the housing outlet so that a high-pressure working fluid introduced into the housing inlet is capable of moving in a direction of the housing outlet; a rotation shaft that passes through the housing and is rotatably coupled to the housing; and a rotor that is integrally coupled to the rotation shaft within the housing flow path and rotates the rotation shaft as the working fluid introduced from a center side of the rotor in an axial direction is injected toward an outer circumference side of the rotor, wherein the rotor comprises first and second rotor plates that are coupled to each other in the axial direction, and an inner flow path on which the working fluid is guided, is formed on a surface of the second rotor plate toward the first rotor plate, and the first rotor plate is formed to cover an entire surface of the inner flow path.
 3. The reaction turbine of claim 1, wherein the first and second flow paths have cross sections that are symmetrical with respect to each other based on a surface on which the first and second rotor plates are coupled together.
 4. The reaction turbine of claim 1, wherein a cross section of each of the first and second flow paths is formed into a semicircular shape.
 5. The reaction turbine of claim 1, wherein a cross section of the inner flow path is formed into a circular shape.
 6. The reaction turbine of claim 2, wherein a cross section of the inner flow path is formed into a semicircular shape.
 7. The reaction turbine of claim 1, wherein the inner flow path is formed when the first and second rotor plates are manufactured using a casting method and is finished using a ball end mill.
 8. The reaction turbine of claim 1, further comprising a nozzle portion that extends from and is formed at a discharge side of the inner flow path and has a smaller cross-sectional area than that of the discharge side of the inner flow path.
 9. The reaction turbine of claim 1, wherein a plurality of rotors are stacked and disposed in a multi-stage manner along the axial direction within the housing flow path, and the working fluid injected from a rotor in a previous stage toward the outer circumference side of the rotor is introduced toward the center side of a rotor in a next stage through the housing flow path.
 10. The reaction turbine of claim 1, wherein at least a part of the inner flow path has an involute curve shape.
 11. The reaction turbine of claim 10, wherein a rotor introduction portion into which the working fluid is introduced in the axial direction and which sends the introduced working fluid to the inner flow path, is formed in a center of the rotor, and an outer circumferential surface of the rotor introduction portion and an outer circumferential surface of the inner flow path are connected to each other so as to constitute at least one arc shape.
 12. A reaction turbine comprising: a housing in which a housing inlet and a housing outlet are formed and a housing flow path that communicates the housing inlet and the housing outlet so that a high-pressure working fluid introduced into the housing inlet is capable of moving in a direction of the housing outlet; a rotation shaft that passes through the housing and is rotatably coupled to the housing; and a rotor assembly that comprises a plurality of rotors, which are stacked and disposed in a multi-stage manner along an axial direction within the housing flow path that are integrally coupled to the rotation shaft, and that rotate the rotation shaft as the working fluid introduced from a center of each of the plurality of rotors in the axial direction is injected toward an outer circumference side of each rotor, wherein the plurality of rotors are integrally formed when two rotor plates are coupled to each other in the axial direction, and first and second flow paths of which cross sections are symmetrical with respect to each other, are formed on surfaces of the rotor plates that face each other, and a combination of the first and second flow paths constitutes one inner flow path.
 13. The reaction turbine of claim 2, wherein the inner flow path is formed when the first and second rotor plates are manufactured using a casting method and is finished using a ball end mill.
 14. The reaction turbine of claim 2, further comprising a nozzle portion that extends from and is formed at a discharge side of the inner flow path and has a smaller cross-sectional area than that of the discharge side of the inner flow path.
 15. The reaction turbine of claim 2, wherein a plurality of rotors are stacked and disposed in a multi-stage manner along the axial direction within the housing flow path, and the working fluid injected from a rotor in a previous stage toward the outer circumference side of the rotor is introduced toward the center side of a rotor in a next stage through the housing flow path.
 16. The reaction turbine of claim 2, wherein at least a part of the inner flow path has an involute curve shape.
 17. The reaction turbine of claim 16, wherein a rotor introduction portion into which the working fluid is introduced in the axial direction and which sends the introduced working fluid to the inner flow path, is formed in a center of the rotor, and an outer circumferential surface of the rotor introduction portion and an outer circumferential surface of the inner flow path are connected to each other so as to constitute at least one arc shape. 